Note: Descriptions are shown in the official language in which they were submitted.
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MASONRY BLOCK WALL SYSTEM
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit of U.S. Provisional Application
No. 60/652,045, filed February 10, 2005.
FIELD
The present disclosure concerns embodiments of a masonry block wall
system, and in particular, a free-standing wall, or fence, constructed of
masonry
blocks preferably without the use of mortar or grout.
BACKGROUND
The construction of a free-standing wall from masonry blocks using known
techniques is time consuming and requires the expensive skills of a mason.
Typically, such walls require frequent vertically extending reinforcing bars
anchored
in a concrete footer extending the length of the wall and horizontal
reinforcing bars
extending through selected courses of the wall. The vertical reinforcing bars
are
typically extended upward through voids in the masonry blocks. The voids
surrounding the vertical and horizontal reinforcing bars typically are filled
with
grout to connect the reinforcing bars to the blocks in the wall.
The expense of conventional materials and the time required for building
these structures using conventional methods limit the use of these otherwise
durable
masonry block systems. Unlike wood fences, masonry block wall systems resist
weathering and provide a permanent structure that requires little, if any, '
maintenance. Block walls also provide excellent security, privacy, and/or
sound
suppression. However, block walls require structural integrity to withstand
wind or
other exterior forces. The fulfillment of these structural requirements is
thought to
necessitate the use of current building materials and techniques. Elimination
of skill
intensive building techniques and materials requiring special skill, and
streamlining
the process for building free-standing block walls would result in substantial
savings
in time, labor costs, and material costs for building such walls.
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SUMMARY
The present disclosure concerns a system for constructing masonry block
walls having spaced-apart pilasters and panels supported by and extending
between
the pilasters. The, system does not require substantial excavation, concrete
grade
beams or skilled labor. In certain embodiments, the pilasters are constructed
from
stacks of pilaster blocks which are secured together using at least one
vertical, post-
tensioned reinforcing member, without the use of grout to connect the
reinforcing
members to the pilaster blocks. The pilasters preferably are supported on
respective
footings or piers spaced at intervals along the wall, therefore eliminating
the
requirement of a continuous footing extending between the pilasters. The
panels are
constructed from courses of panel blocks, and do not require the use of mortar
to
connect adjacent blocks. Instead, block-connecting elements (e.g., a plastic
connecting pin or plug) can be used to connect vertically adjacent blocks in
the
courses, with selected one or more courses being reinforced with horizontally
extending, post-tensioned reinforcing members. Again, grout is not needed to
connect the reinforcing members to the panel blocks. The masonry block wall
system therefore greatly simplifies and expedites the construction of a wall
because
substantially less concrete is need as compared to prior systems and the
expensive
skills of a mason are not required.
The pilasters in particular embodiments are constructed from at least two
laterally spaced-apart stacks of pilaster blocks positioned on opposite sides
of the
wall. The spacing between the stacks of pilaster blocks is sufficient to
receive an
end portion of a panel. The pilasters therefore provide an arrangement in
which a
panel can be supported in an upright position by virtue of one end portion
being
positioned between two stacks of blocks of a first pilaster and the opposite
end
portion of the panel being positioned between two stacks of blocks of a second
pilaster, preferably without any mechanical fasteners for securing or
connecting the
panels directly to the pilasters. Advantageously, the pilasters support the
panel, but
yet allow for a certain degree of panel movement relative to the stacks of
pilaster
blocks to enhance the stability of the wall.
The pilaster arrangement further simplifies wall construction due to the
existence of a large degree of dimensional forgiveness between the pilasters
and the
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panels. More specifically, the void in each pilaster that receives the end
portion of
one or more panels is large enough to accommodate variations in the length of
a
panel or the spacing between the pilasters that may occur during the
construction of
the wall. Consequently, a high degree of precision with regard to pilaster
spacing or
panel size is not required in the construction of a wall, as is required in
prior
systems.
In one representative embodiment, a masonry block wall structure comprises
at least first and second footings formed in the ground and spaced along the
wall
structure. First and second pilasters are supported on the first and second
footings,
respectively, with each pilaster comprising at least a first stack of pilaster
blocks and
at least a second stack of pilaster blocks positioned on opposite sides of the
wall
structure from each other. At least one vertical post-tensioned reinforcing
member
extends upwardly through and reinforces each pilaster. The wall structure
further
includes at least one panel comprising a plurality of courses of panel blocks,
the
courses being without any mortar or grout between adjacent panel blocks. The
panel
has first and second end portions, the first end portion being positioned
between and
abutting the first and second stacks of pilaster blocks of the first pilaster
and the
second end portion being positioned between and abutting the first and second
stacks of pilaster blocks of the second pilaster such that the panel is
supported by
and extends between the first and second pilasters.
In another representative embodiment, a masonry block wall structure
comprises first and second pilasters located at spaced apart locations along
the wall
structure. Each pilaster comprises at least a first stack of pilaster blocks
and at least
a second stack of pilaster blocks positioned on opposite sides of the wall
structure
from each other and at least one vertical post-tensioned reinforcing member
extending upwardly through and reinforcing the pilaster. The wall structure
further
includes at least one panel comprising a plurality of courses of panel blocks,
the
panel having first and second end portions. The first end portion is
positioned
between the first and second stacks of pilaster blocks of the first pilaster
and the
second end portion is positioned between the first and second stacks of
pilaster
blocks of the second pilaster such that the panel is supported by and extends
between the first and second pilasters.
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In yet another representative embodiment, a method for forming a masonry
block wall structure comprises forming at least first and second footings at
spaced
apart locations in the ground. First and second pilasters are formed on the
first and
second footings, respectively, with each pilaster comprising at least a first
stack of
pilaster blocks and at least a second stack of pilaster blocks formed at a
location
spaced from the first stack, and a vertical reinforcing member extending the
height
of the pilaster. A panel is constructed between the pilasters by forming at
least a
first lower course of panel blocks extending between the pilasters and at
least a
second upper course of panel blocks overlying the first course and extending
between the pilasters. Each course of panel blocks has a first end and a
second end,
wherein portions of the panel blocks at the first ends of the courses are
positioned
between and abut against the first and second stacks of pilaster blocks of the
first
pilaster and portions of the panel blocks at the second ends of the courses
are
positioned between and abut against the first and second stacks of pilaster
blocks of
the second pilaster such that the panel is supported by and extends between
the first
and second pilasters. The method further includes tensioning the reinforcing
members to reinforce the pilasters.
The foregoing and other features and advantages of the invention will
become more apparent from the following detailed description of several
embodiments, which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a free-standing wall constructed from a
plurality of masonry blocks, according to one embodiment.
FIG. 2 is an enlarged, fraginentary front elevational view the wall shown in
FIG. 1.
FIG. 3 is an enlarged, fragmentary top plan view of the wall shown in FIG.
1.
FIG. 4 is a vertical cross-sectional view of a pilaster of the wall shown in
FIG. 1.
FIG. 5 is an end view of a reinforced panel of the wall shown in FIG.1
formed from a plurality of panel blocks.
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FIG. 6 is an enlarged, fragmentary top plan view of a wall similar to FIG. 3,
but having a pilaster construction incorporating two vertical reinforcing
members.
FIG. 7 is a vertical cross-sectional view of the pilaster shown in FIG. 6.
FIG. 8A is a perspective view of a panel block, according to one
embodiment, used to form panels in a wall.
FIG. 8B is an end elevational view of the panel block shown in FIG. 8A.
FIG. 8C is a bottom plan view of the panel block shown in FIG. 8A.
FIG. 9A is a perspective view of a pilaster block, according to one
embodiment, used to form pilasters in a wall.
FIG. 9B is a bottom plan view of the pilaster block shown in FIG. 9A.
FIG. 9C is an end elevational view of the pilaster block shown in FIG. 9A.
FIG. 9D is a perspective view of another pilaster block, which has the same
overall shape of the pilaster block of FIG. 9A but is about 3/4 the length of
the block
of FIG. 9A.
FIG. 9E is a perspective view of another pilaster block, which has the same
overall shape of the pilaster block of FIG. 9A but is about %2 the length of
the block
of FIG. 9A.
FIG. 10 is a perspective view of a block-connecting element, according to
one embodiment, used for connecting vertically adjacent blocks.
FIG. 11 is a perspective view of a block-connecting element having a
generally pin-shaped construction.
FIG. 12 is a cross-sectional view showing the use of the block-connecting
elements of FIG. 10 in the construction of a pilaster.
FIG. 13 is a fragmentary, cross-sectional view of a panel illustrating the use
of the block-connecting elements of FIGS. 10 and 11 to interconnect vertically
adjacent block in the construction of the panel.
FIG. 14 is a top plan view of a corner pilaster used to form a 90-degree
corner in a wall.
FIG. 15 is a top plan view of a pilaster used to form a T-shaped intersection
of wall panels in a wall.
FIG. 16 is a top plan view of a free-standing wall constructed from a
plurality of masonry blocks, according to another embodiment.
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FIG. 17 is a perspective view of a pilaster block used to form the field
pilasters in the wall shown in FIG. 15.
FIG. 18 is a top plan view of a pilaster block used to form the corner
pilasters
in the wall shown in FIG 15.
FIG. 19 shows an exemplary wind pressure table that can be used to
determine the anticipated wind pressure on a wall to be constructed.
FIGS. 20 and 21 show exemplary design tables that can be used to determine
certain design criteria for constructing a wall.
FIG. 22 is a schematic, top plan view of an exemplary mold layout for
forming multiple panel blocks.
FIG. 23 is a schematic, top plan view of an exemplary mold layout for
forming multiple pilaster blocks.
FIG. 24 is a schematic, top plan view of an exemplary mold layout for
forming pilaster blocks and panel blocks.
FIG. 25A is a perspective view of a panel block, according to another
embodiment, used to form panels in a wall.
FIG. 25B is an end elevational view of the panel block shown in FIG. 25A.
FIG. 25C is a bottom plan view of the panel block shown in FIG. 25A.
FIG. 26A is a perspective view of a capping block, according to one
embodiment.
FIG. 26B is an end elevational view of the capping block shown in FIG.
26A.
FIG. 27 is a fragmentary, cross-sectional view of a pilaster having a capping
layer constructed from four capping blocks, according to one embodiment.
FIG. 28 is a fragmentary, cross-sectional view of a pilaster having a capping
layer constructed from four capping blocks, according to another embodiment: -
DETAILED DESCRIPTION
As used herein, the singular forms "a," "an," and "the" refer to one or more
than one, unless the context clearly dictates otherwise.
As used herein, the term "includes" means "comprises." For example, a
device that includes or comprises A and B contains A and B but may optionally
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contain C or other components other than A and B. A device that includes or
comprises A or B may contain A or B or A and B, and optionally one or more
other
components such as C.
Referring first to FIGS. 1 and 2, there is shown a free-standing wall
structure
10 (e.g., a fence), according to one embodiment, comprising one or more panels
12
supported between pilasters. The pilasters can be a field pilaster 14
positioned at the
ends of two adjacent panels 12 positioned end-to-end in a 180-degree
relationship
with respect to each other in one side of the wall structure (as shown in FIG.
1), a
corner pilaster 16 (FIG. 14) positioned at a 90-corner of the wall structure,
or a
pilaster 78 (FIG. 15) positioned at a T-shaped juncture of the wall structure.
The
panels 12 are constructed from a plurality of panel blocks 18 placed in rows,
or
courses, of such blocks. The end blocks (the blocks at the end of each course)
of
every other course comprise "half-blocks" 19, which are 1/2 the length of
panel
blocks 18, so as to form a "running bond" pattern of blocks in the panels 12,
as
described in detail below. The pilasters 14, 16 are constructed from a
plurality of
pilaster blocks 20, as further described below.
Desirably, capping blocks 128 are disposed on top of each pilaster 14, 16 and
a course of capping blocks 130 is formed on top of the uppermost course of
panel
blocks in each panel 12. Capping blocks 128 have voids, or openings, 140
formed
in the bottom surfaces of the blocks to receive plates 36, washers 38, nuts
40, and
the upper portions of reinforcing members 24 (described below) extending above
the
uppermost pilaster blocks 20. Capping blocks 128 and 130 also can be formed
with
horizontal openings (not shown) extending completely through the blocks in a
direction longitudinally of the wall to allow utility conduits to be placed on
top of
the uppermost courses of panel blocks 18 and pilaster blocks 20 along the
length of
the wall.
A plurality of spaced apart footings, or piers, 22 are formed in the ground to
support the pilasters 14, 16 (although only field pilasters 14 are shown in
FIG. 1).
The footings 22 can be reinforced with re-bars 42 as shown or other
reinforcement
devices. The ends of the panels 12 desirably are supported on the footings to
increase the overall load on the footings, and therefore better resist tipping
forces.
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The pilasters 14, 16 desirably are reinforced with one or more post-tensioned
vertical reinforcing members 24 secured to the footings 22 and extending
upwardly
through the pilasters. Typically, each pilaster is provided with one or two
vertical
reinforcing members, depending on the particular application. In the
embodiment
shown in FIGS. 1-3, each pilaster 14 has one vertical reinforcing member 24,
which
preferably is centrally located within the respective pilaster. FIGS. 6 and 7
(described in greater detail below) illustrate a pilaster construction using
two vertical
reinforcing members, according to one embodiment.
The reinforcing members 24 typically are steel rods or bars, but can be any
elongated member that can be post-tensioned to reinforce the pilasters. In
particular
embodiments, for example, the reinforcing members 24 comprise steel rods
having a
diameter of 0.50", 0.625", or 0.75", although smaller or larger diameter rods
also
can be used. In alternative embodiments, the reinforcing members 24 can be
flexible cables (e.g., steel cables) or the like that can be placed in tension
to
reinforce the pilasters.
As shown in FIGS. 3 and 4, each pilaster 14 is formed from two laterally
spaced-apart stacks of pilaster blocks 20 positioned on opposite sides of the
wall
structure 10 and partially overlapping adjacent end portions of two panels 12
to form
a substantially closed void 26 between the adjacent ends of the panels and
extending
the height of the pilaster. When one vertical reinforcing member 24 is used to
reinforce the pilaster 14 (as depicted in FIGS. 1-3), the reinforcing member
24
desirably is centrally located within the void 26.
The lower end portions of the reinforcing members 24 can be secured to the
footings 22 using any suitable techniques or mechanisms. In the embodiment
shown
in FIGS. 1-3, for example, each pilaster is provided with a vertically upright
steel
rod 28 embedded in the respective footing 22 and extending upwardly into the
void,'
26. As best shown in FIG. 2, each rod 28 has a threaded lower end portion 110
that
extends through a horizontal plate 112 embedded in the footing 22. The rod 28
can
be secured to the plate 112 using a washer 116 and nuts 114 tightened onto the
threaded outer surface of the lower end portion 110 on opposite sides of the
plate
112. The rod 28 has a threaded upper end portion secured to an internally
threaded
coupling member 30. Coupling member 30 has an internally threaded bore sized
to
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receive a threaded lower end portion 32 of the reinforcing member 24 and the
threaded upper end portion of the rod 28.
In another embodiment, "J-hooks" (not shown) can be used instead of rods
28. In the latter embodiment, the J-hooks have their lower end portions
embedded
in the footings and their upper end portions connected to threaded coupling
members
30 that are secured to the reinforcing members 24. In yet another embodiment,
the
reinforcing members 24 are secured to the footings 22 by inserting the lower
end
portions of the reinforcing members 24 into the footings 22 before the
concrete sets.
The reinforcing members can have curved or J-shaped lower end portions when
the
lower end portions are embedded directly in the footings.
As best shown in FIG. 2, each reinforcing member 24 has a threaded upper
end portion 34 extending through a rigid plate 36 and a washer 38, with a nut
40
tightened onto the end portion 34 above the washer 38. As depicted in FIG. 3,
the
length of the plate 36 is greater than the width of the void 26, and therefore
spans the
width of the void and partially overlaps the two top pilaster blocks 20 in the
pilaster
14. Tightening the nut 40 against the plate 36 tensions the reinforcing member
24
and applies a corresponding compressive force against the pilaster blocks 20,
thereby reinforcing the pilaster. Optionally, a gasket material (e.g., latex
cement)
can be applied to the upper surfaces of the top pilaster blocks 20 to provide
a bearing
surface for the plate 36.
In certain embodiments, washers 38 can comprise direct tension indicating
(DTI) washers, such as commercially available from Applied Bolting Technology
Products, Inc. (Bellows Falls, Vermont). When a reinforcing member is
tensioned
to the desired, predetermined tension, the force applied to the washer causes
the
washer to emit a colored liquid as a visual indicator that the reinforcing
member 24
has been properly tensioned.
FIGS. 9A-9C are enlarged views of a pilaster block 20. The pilaster block
20 is generally rectangular and includes a plurality of openings, or slots, 44
extending the height of the block. Hence, the slots 44 open to the upper and
lower
surfaces of the block 20. The slots 44 are equally spaced from each other
lengthwise
of the block along a line equally spaced between the front and back surfaces
46, 48,
respectively, of the block. The openings 44 are sized to receive a block-
connecting
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element (e.g., the block-connecting element 50 shown in FIG. 10 or the block-
connecting element 52 shown in FIG. 11) for connecting vertically adjacent
blocks
in a pilaster, as further described below. The configuration of the pilaster
block is
not limited to that shown in FIGS. 9A-9C. Accordingly, the pilaster block 20
can be
any of various other geometric shapes, such as a trapezoid (FIG. 17), square,
a
rectangle, a parallelogram (FIG. 18), a diamond, or various combinations
thereof.
Also, in other embodiments, the block 20 can be formed without any openings
44.
As shown in FIG. 9A, the front surface 46 and the end surfaces 49 of the
pilaster block 20 desirably are provided with a "split-face" texture
resembling
natural stone that can be accomplished by suitable splitting techniques.
Alternatively, the front surface 46 and the end surfaces 49 of the block can
be
provided with a roughened surface resembling natural stone using the mold
apparatus described in U.S. Patent Application Publication No. 2003-0164574,
entitled "Apparatus and Methods for Making a Masonry Block with a Roughened
Surface," which is incorporated herein by reference.
When constructing the pilaster 14, either block-connecting elements 50 (FIG.
10) or block-connecting elements 52 (FIG. 11) can be used to facilitate
alignment of
the pilaster blocks 20 as they are stacked on top of each other. The block-
connecting elements 50, 52 also function to connect vertically adjacent blocks
to
better resist shear forces on the wall structure 10.
As shown in FIG. 10, the block-connecting element 50 comprises an
enlarged, generally rectangular lower portion 54 and a generally cylindrical,
pin-
shaped upper portion 56. The block-connecting element 50 can be referred to an
alignment "plug" because of its enlarged lower body portion. Referring to FIG.
12,
when block-connecting elements 50 are used in the construction of a pilaster
14, the
lower portion 54 of an element 50 is inserted into an opening 44 of a pilaster
block
20 through the upper surface of that block. The upper portion 56 of the block-
connecting element is inserted into a corresponding opening 44 of an overlying
pilaster block 20 as it is stacked on top of the previously laid block. In the
illustrated example, two block-connecting elements 50 are used to interconnect
a
pair of vertically adjacent pilaster blocks 20. However, greater or fewer
number of
block-connecting elements can be used, depending on the particular
application.
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Block-connecting elements 50 typically are placed in the outermost openings 44
in
the blocks (the openings 44 closest to the block ends) as shown in FIG. 12, in
the
event vertical reinforcing members 24 are placed in the inner openings 44
(FIGS 6
and 7).
Block-connecting elements 52 (FIG. 11) can be used in lieu of or in addition
to block-connecting elements 50 in forming a pilaster. As shown in FIG. 11,
block-
connecting element 52 comprises a generally pin-shaped structure (and
therefore can
be referred to as an "alignment pin"). Block-connecting element 52 includes a
generally cylindrical upper portion 58, a generally cylindrical lower portion
60, an
annular apron 62 separating the upper and lower portions, and a plurality of
angularly spaced ribs 64 extending the length of the lower portion 60. When
block-
connecting elements 52 are used in the construction of a pilaster, the lower
portion
60 of a block-connecting element is inserted into an opening 44 of a pilaster
block
positioned in one of stacks forming the pilaster 14. The block-connecting
15 element 52 is secured in place by a frictional engagement between the ribs
64 and
the inner surface of the opening 44. The upper portion 58 is inserted into a
corresponding opening 44 of an overlying pilaster block 20 as it is stacked on
top of
the previously laid block.
In certain embodiments, as shown in FIG. 4, one or more clips or connectors
20 118 can be used in the construction of a pilaster to interconnect pilaster
blocks 20 on
opposite sides of the void 26 to further stabilize the pilaster. Each clip 118
spans the
width of the void and has two downwardly projecting leg portions 119, each of
which is received in a respective opening 44 in a pilaster block 20. The top
surfaces
of the pilaster blocks 20 can be fortned with small depressions or recesses to
receive
the clips 118. The clips 118 can be formed from, for example, strips of 16-
gage
metal. Typically, a clip 118 is installed about every two feet along the
height of the
pilaster, although the actual number and spacing of the clips 118 will depend
on the
particular installation.
FIGS. 6 and 7 illustrate the construction of a pilaster 14 using two post-
tensioned, vertical reinforcing members 24. The pilaster 14 shown in FIGS. 6
and 7
is constructed in the same manner as the pilaster shown in FIGS. 2 and 3,
except that
two reinforcing members 24 are used, each of which extends vertically through
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openings 44 in a stack of pilaster blocks 20. The reinforcing members 24
desirably
are offset from each other in the direction of the wall in the manner shown in
FIG. 6,
rather than directly across from each other in the wall, to better distribute
the
compression force of the rigid plate 36 to the stacks of pilaster blocks 20.
If desired,
additional reinforcing menibers 24 can be installed in the other openings 44
in the
stacks of pilaster blocks or in the void 26 between the stacks of pilaster
blocks.
FIG. 14 illustrates one possible approach for constructing a corner pilaster
16
that forms a 90-degree corner in a wall structure. As shown, a first stack 64
of
pilaster blocks 20 is formed on a footing 22 as previously described so as to
form
one side of the pilaster 16. A second stack 66 of pilaster blocks 68 is formed
at a
90-degree angle with respect to the first stack 64. A third stack 70 of
pilaster blocks
72 is formed at a 90-degree angle with respect to the first stack 64 and is
spaced
from the first stack 64 the width of a panel 12 and from the second stack 66
the
width of another panel 12' extending at a 90-degree angle with respect to
panel 12.
The end portion of panel 12 is disposed between the first stack 64 and the
third stack
70 and the end portion of panel 12' is disposed between the second stack 66
and the
third stack 70 so as to form a closed void 74 extending the height of the
pilaster 16.
The length of pilaster blocks 68 forming the second stack 66 is 3/4 the length
of
pilaster blocks 20 while the length of pilaster blocks 72 forming the third
stack is %2
the length of pilaster blocks 20. In this manner, the pilaster 16 forms a
horizontal
footprint that fits within the square footprint of a capping block 128 placed
on top of
the pilaster, as depicted in FIG. 14.
A vertical reinforcing member 24 is installed in the void 74 and tensioned in
the manner described above to reinforce the pilaster 16. The reinforcing
member
extends through a rigid plate 76 that at least partially overlaps the
uppermost pilaster
blocks in stacks 64, 66, 70 and the uppermost panel blocks 18 at the ends of
panels
12, 12'. While only one vertical reinforcing member 24 is shown in the
illustrated
embodiment, multiple reinforcing members 24 can be used in the construction of
the
pilaster 16.
Pilaster block 68 (best shown in FIG. 9D) can be formed by splitting or
cutting a pilaster block 20 along a line Ll (FIGS. 9A and 9B) spaced 1/4 the
length of
the block 20 from one end of the block (i.e., at a location between one of the
outer
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openings 44 and the adjacent inner opening 44). Pilaster block 72 (best shown
in
FIG. 9E) can be formed by splitting or cutting a pilaster block along a line
L2 (FIGS.
9A and 9B) spaced equidistant between the opposite ends of the block 20 (i.e.,
between the two inner openings 44). Advantageoi,usly, pilaster blocks of all
the same
size can be provided for forming a corner pilaster to reduce manufacturing
costs,
with blocks 68, 72 being formed at the job site using conventional splitting
techniques.
FIG. 15 illustrates a pilaster 78 used to form a T-shaped junction of panels
12, 12', and 12" in a wall. The pilaster 78 comprises a first stack 132 of
pilaster
blocks 20 on one side of the wall surface defined by panels 12 and 12'. Second
and
third stacks 134, 136, respectively, of pilaster blocks 72 are formed in a
parallel
relationship with respect to each other and are spaced from each other the
width of
panel 12". The second and third stacks 134, 136 are oriented at a 90-degree
angle
with respect to the first stack 132 and are spaced therefrom the width of
panels 12
and 12'. The end portion of panel 12 is disposed between the first stack 132
and the
second stack 134, the end portion of panel 12' is disposed between the first
stack
132 and the third stack 136, and the end portion of panel 12" is disposed
between the
second stack and the third stack to form a substantially closed void extending
the
height of the pilaster 78. One or more post-tensioned, vertical reinforcing
members
24 can be used to reinforce the pilaster.
As best shown in FIGS. 8A-8C, the panel block 18 in the illustrated
configuration is generally rectangular and comprises opposed, generally
parallel first
and second faces 80, 82, respectively, sides 84 extending between respective
ends of
the first and second faces 80, 82, an upper surface 86 and a parallel lower
surface 88.
In other embodiments, however, the panel block 18 can be any of various other
geometric shapes, such as a square, a trapezoid, a parallelogram, a diamond,
or
various combinations thereof.
As best shown in FIG. 8B, the panel block 18 includes a horizontally
extending opening, or slot, 94 formed in the lower surface 88 and extending
the
block length (measured between the sides 84). The slot 94 is sized to receive
a post-
tensioned horizontal reinforcing member 100 for reinforcing a course of panel
blocks 18, as further described below.
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The first and second faces 80, 82 (which are exposed in the front and back
surface of a panel 12) desirably are provided with a roughened surface texture
(as
shown in FIG. 8A), for example, using conventional splitting techniques or the
technique disclosed in U.S. Patent Application Publication No. 2003-0164574.
The
illustrated panel block 18 also is formed with a central core, or opening, 90
desirably
extending from the slot 94 to the upper surface 86 of the block. The panel
block 18
also can be formed with two "half cores" or openings 92 formed in the sides 84
and
extending the heiglit of the block. As shown in FIG. 3, when the panel blocks
18 are
placed side-by-side in courses, the adjacent sides 84 of two panel blocks abut
each
other so that the openings 92 of two adjacent blocks form a closed void. The
block
18 also can be formed with optional openings 96 on opposite sides of the
central
core 90 and extending from the slot 94 to the upper surface 86 of the block.
Openings 90 and 92 are sized to receive a block-connecting element 50 (FIG.
10) for
connecting vertically adjacent blocks. Openings 96 are sized to receive a
block-
connecting element 52 (FIG. 11) for connecting vertically adjacent blocks.
In particular embodiments, the top of the slot 94 is approximately midway
between the upper and lower surfaces 86, 88, respectively, as depicted in
panel
block 18' shown in FIGS. 25A-25C. Thus, when a course of panel blocks is
reinforced with a horizontal reinforcing member 10.0, the reinforcing member
can be
positioned at about the middle of the height of the course to balance the
compressive
load of the reinforcing member between the upper and lower surfaces of the
panel
blocks in the course. Placing the reinforcing member 100 at this location
maximizes
the retention capability of the reinforcing member.
Due to the slot 94 having a greater height in the block, portions of the block
can be susceptible to breakage during shipment or handling of the block. To
minimize such breakage, the panel block 18' can include sacrificial portions
144
(also referred to as "knock-out" portions) (shown in dashed lines in FIGS. 25A
and
25B) where openings 92 would normally intersect sides 84 of the block. The
inner
surfaces of the sacrificial portions 144 can be formed with notches 145
extending the
height of the block to facilitate removal of the sacrificial portions 144. The
sacrificial portions 144 interconnect the concrete portions separated by
openings 92
and therefore minimize chipping or breakage of the concrete at the ends of the
block.
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Prior to installation, sacrificial portions 144 are removed to extend openings
92 to
the sides 84 of the block.
As best shown in FIGS. 1 and 13, the panel blocks 18 are stacked in courses
so as to form a "running bond"; that is, the panel blocks 18 are placed in a
staggered
manner such that each panel block 18 straddles two panel blocks in a lower
course,
except where a half block 19 is used at the ends of a course. Half blocks 19
can be
formed, for example, by splitting panel blocks 18 in half or by separately
molding
blocks that are %a the length of the panel blocks 18.
When forming the courses of panel blocks 18, either alignment plugs 50
(FIG. 10) or alignment pins 52 (FIG. 11) can be used to interconnect
vertically
adjacent blocks. FIG. 13 illustrates the use of both block-connecting elements
50
and 52, although one or the other type of connector can be used; it is not
required or
necessary to use both types of block-connecting elements when constructing a
panel
12.
As shown in FIG. 13, if block-connecting elements 52 are used, the lower
portions 60 of the block-connecting elements are inserted into the openings 96
of the
blocks in a lower course. The upper portions 58 of the block-connecting
elements
52 are inserted upwardly into corresponding slots 94 of overlying blocks as
they are
placed over the blocks in the previously formed course. Typically, a block-
connecting element 52 is inserted into each opening 96 of a block as a course
is
formed so that each block will be connected to two blocks in an overlying
course in
the staggered manner shown in FIG. 13.
When constructing a panel using block-connecting elements 50, the lower
portion 54 is inserted into the void formed by the openings 92 of two abutting
blocks
in the same course. The upper portion 56 of the block-connecting element is
inserted upwardly into a-slot 94 of an overlying block as it is placed over
the two
lower blocks in the staggered manner shown in FIG. 13. Alternatively, the
blocks in
vertically adjacent courses can be interconnected by placing the lower
portions 54 of
block-connecting elements 50 in the central openings 90 of the blocks in the
lower
course rather than in the voids formed by openings 92.
Selected one or more courses of a panel 12 can be reinforced using a post-
tensioned horizontal reinforcing member 100. In particular embodiments, as
shown
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in FIG. 1, the lowermost course and uppermost course of blocks in each panel
12 are
reinforced with a post-tensioned horizontal reinforcing member 100 extending
through the slots 94 of the panel blocks 18 in those courses. However,
depending on
the height of the wall structure and the anticipated loads on the wall
structure,
additional courses (e.g., every course, every other course or every third
course) can
be reinforced with a horizontal reinforcing member 100. The reinforcing
members
100 typically are steel rods or bars, but can be any elongated member that can
be
placed in tension to reinforce the courses of panel blocks 18. In certain
embodiments, for example, the reinforcing members 100 comprise steel rods
having
a diameter of 0.50", 0.625", or 0.75", altl=iough smaller or larger diameter
rods also
can be used.
As best shown in FIGS. 3 and 5, the opposite end portions 102 of each
reinforcing member 100 have threaded outer surfaces and extend through
respective
rigid plates 104 and washers 106 at the ends of the panel 12. Nuts 108 are
tightened
onto the end portions 102 to tension the reinforcing member, which applies a
compressive force to the panel blocks in the course, thereby reinforcing that
course
of blocks. Desirably, a gasket material (e.g., latex cement) is applied to the
end
surfaces of the blocks at the ends of the course adjacent the rigid plates 104
prior to
post-tensioning the reinforcing member so that the plates bear against the
gasket
material. When the first or lowermost course in each panel 12 is reinforced
with a
reinforcing member 100, the lowermost course serves as a "rail" or "ledger"
for
supporting successive courses. Advantageously, a continuous concrete footing
extending between the pilasters 14, 16 is not required to support the panels
12, as in
conventional free-standing block walls. The elimination of a continuous
footing
represents a substantial reduction in material and labor costs for
constructing the
wall structure. The reinforced courses can be constructed in the field as
thewall
structure is being built. Alternatively, reinforced courses with a post-
tensioned
reinforcing member 100 can be pre-assembled and shipped to the job site,
thereby
reducing labor costs and facilitating installation.
Depending on the size of the panels 12 used, each panel 12 may be further
reinforced using one or more post-tensioned vertical reinforcing members 120
extending the height of the panel (one such reinforcing member is used in the
full
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panel shown in FIG. 1). The reinforcing member 120 extends vertically through
the
cores 90 of the panel blocks 18 and the voids formed by half-cores 92 of
abutting
panel blocks 18. The reinforcing member 120 has a threaded upper end portion
extending above the top course of panel blocks and a threaded lower end
portion
extending below the bottom course of panel blocks. A rigid plate 122, a washer
124,
and a nut 126 are disposed on each of the upper and lower portions of the
reinforcing member 120. The nuts 126 are tightened to tension the reinforcing
member 120 and apply a compressive force to the panel between the plates 122.
In applications where greater reinforcement of the panels is required, such as
in high wind applications (e.g., 120 mph wind or greater), the lower ends of
reinforcing members 120 can be secured to respective concrete footings (not
shown)
in the ground. In this manner, tensioning the reinforcing members 120
compresses
that panels downwardly against the footings to better resist lateral forces
(e.g., wind)
applied to the panels. The footings used for this purpose can be the same as
footings
22 used to support the pilasters. The same techniques can be used to secure
reinforcing members 120 to the footings as described above for securing
reinforcing
members 24 to footings 22. In an alternative embodiment, the footings can be
conventional truncated pyramidal pier blocks, such as commonly used in the
construction of wood decks. In this alternative embodiment, the reinforcing
members 120 can be sized to extend completely through the pier blocks with
nuts
tightened onto the lower end portions of the reinforcing members below the
pier
blocks.
FIGS. 26A and 26B show a capping block 300, according to another
embodiment, that can be used form a capping layer, or course, on top of a
pilaster.
The capping block 300 has a trapezoidal cross-section (as best shown in FIG.
26B)
with parallel upper and lower surfaces 302 and 304, respectively, opposing and
parallel end surfaces 306, and first and second side surfaces 308 and 310,
respectively, extending between respective ends of the upper and lower
surfaces
302, 304. The first side surface 308 extends perpendicular to the upper and
lower
surfaces, while the second side surface 310 extends at an acute angle with
respect to
the upper surface 302 such that the block tapers from the upper surface to the
lower
surface.
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FIG. 27 shows a capping layer formed from four capping blocks 300a, 300b,
300c, 300d arranged side-by-side on top of a pilaster 14. The inner capping
blocks
300b, 300c are arranged to form a triangular void that receives the upper end
of the
reinforcing rod 24 and the washer 38 and nut 40 mounted thereon. The outer
capping blocks 300a, 300d are positioned with their perpendicular sides 308
abutting
the perpendicular sides 308 of the inner capping blocks 300c, 300d so as to
form a
capping layer that tapers from top to bottom. FIG. 28 shows an alternative
configuration of a capping layer constructed from four capping blocks 300a,
300b,
300c, 300d. In the capping layer of FIG. 28, the outer capping blocks 300a,
300d
are positioned upside down with their respective surfaces 304 forming the
upper
surface of the capping layer so that the capping layer tapers from bottom to
top.
The block wall system described herein provides a durable and secure free-
standing wall system that can be economically installed without skilled labor
and
with substantial reductions in material costs and labor costs over
conventional free-
standing block wall systems. Notably, grout is not required to attach any of
the
horizontal or vertical reinforcing members to the pilaster blocks or to the
panel
blocks, nor is mortar required in forming each course of pilaster and panel
blocks.
The elimination of grout and mortar greatly simplifies the construction
process while
eliminating the need for a mason or other skilled worker to construct the
wall.
Moreover, the elimination of a continuous footing along the fence line reduces
material costs and labor expenses. The resulting block wall structure will be
less
expensive while providing the necessary system strength and integrity.
In addition, the pilasters advantageously support the panels 12 without any
mechanical fasteners directly securing or attaching the panels to the
pilasters. This
arrangement allows the panels to "float" or move slightly within the spaces
between
the stacks of pilaster blocks to provide a greater degree of stability. Such
movement
can be caused by, for example, thermal expansion or contraction, seismic
forces, or
uneven settlement of the soil along the length of the wall structure.
The pilaster arrangement further simplifies wall construction due to the
existence of a large degree of dimensional forgiveness between the pilasters
and the
panels. Explaining further, the panels are maintained in their upright
positions by
virtue of the panel end portions being positioned between stacks of the
laterally
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spaced-apart pilaster blocks without mechanical fasteners securing the end
portions
to the pilasters. The void in each pilaster that receives the adjacent end
portions of
two panels is large enough to accommodate variations in the length of a panel
or the
spacing between the pilasters that may occur during the construction of the
wall. In
effect, a high degree of precision with regard to pilaster spacing or panel
size is not
required in the construction of a wall, as is required in prior systems.
In an exemplary implementation of the illustrated embodiment, the panel
block 18 has a height of about 8 inches, a length extending between the sides
84 of
about 18 inches, and a width extending between the first and second faces 80,
82 of
about 4-6 inches, with a width of about 5 inches being a specific example. The
pilaster block 20 has a height of about 8 inches, a length of about 16 inches,
and a
width extending between the first and second faces 46, 48 of about 4-6 inches,
with
a width of about 5 inches being a specific example. Of course, these specific
dimensions (as well as other dimensions provided in the present specification)
are
given to illustrate the invention and not to limit it. The dimensions provided
herein
can be modified as needed in different applications or situations.
Although less desirable, in alternative embodiments, grout can be used to
secure the horizontal and/or vertical reinforcing members to the blocks of the
wall.
For example, grout can be used to secure horizontal reinforcing members 100 to
the
panel blocks 18. When grout is used to secure a reinforcing member, post
tensioning techniques need not be applied to the reinforcing member; that is,
the
reinforcing member can be a conventional steel rod that is not placed in
tension.
Additionally, if desired for a particular application, conventional mortared
joints can
be used in the construction of the pilasters and/or the panels.
While the illustrated blocks 18, 19, 20, 68, 72 have pin holes or openings for
accommodating connecting pins or plugs, other techniques or mechanisms can be
used to interconnect vertical adjacent blocks. In one implementation, for
example, a
suitable adhesive can be applied between successive courses in the panels 12.
In
another implementation, the panel blocks can have an interlocking tongue-and-
groove configuration. In another implementation, vertical reinforcing members
can
be extended through panel blocks in each course of a panel and post-tensioned
to
compress the blocks in the vertical direction.
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FIG. 22 shows an exemplary mold assembly 186 for forming five 4" x 18"
panel blocks 18. The mold includes an outer frame 187 surrounding end plates
188,
side plates 189 and separating plates 190 separating the blocks 18 in the
mold. The
inner surfaces of end plates 188 and both side surfaces of plates 190
contacting the
blocks 18 can have projections (not shown), which form a roughened surface
texture
on the front and back surfaces 80, 82 of the blocks 18 as the blocks are
removed
from the mold, as described in U.S. Patent Application Publication No. 2003-
0164574. The mold can be modified as desired to accommodate greater or fewer
number of blocks or larger or smaller blocks.
FIG. 23 shows an exemplary mold assembly 192 for forming five 4" x 16"
pilaster blocks 20. The mold includes an outer frame 187 surrounding end
plates
193, side plates 194, and separating plates 195 separating the blocks 20 in
the mold.
The inner surfaces of end plates 193 and side plates 194 and the side surfaces
of
separating plates 195 contacting the front surfaces 46 of the blocks can have
texture-
forming projections for forming roughened surface textures on the front
surfaces 46
and the end surfaces 49 of the blocks. The mold can be modified as desired to
accommodate greater or fewer number of blocks or larger or smaller blocks.
In the disclosed embodiment, the panel blocks 18 and the pilaster blocks 20
have the same overall rectangular shape and similar dimensions, which allows,
the
molds for forming the panel blocks and the pilaster blocks to be easily
modified for
forming either type of block, thereby reducing manufacturing costs. For
example, a
mold assembly 192 for forming the pilaster blocks 20 can be easily assembled
by
using the outer frame 187 from a mold assembly 186 and replacing the end
plates,
side plates and the separating plates from mold assembly 186 with those
required for
mold assembly 192. This obviates the need for two separate mold assemblies for
forming the panel blocks and the pilaster blocks.
Additionally, multiple panel blocks and pilaster blocks can be formed
simultaneously in the same mold. For example, FIG. 24 shows an exemplary mold
assembly 196 for forming three 4" x 18" panel blocks 18 and two 4" x 16"
pilaster
blocks 20, although the mold can be modified as desired for forming a
different
combination of such blocks. The mold assembly includes an outer frame 187
surrounding end plates 197a, 197b, side plates 198a adjacent the ends of the
panel
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blocks 18, side plates 198b adjacent the end surfaces 49 of the pilaster
blocks 20,
and separating plates 199a and 199b separating the panel blocks 18 and the
pilaster
blocks 20. Texture-forming projections can be provided on the inner surfaces
of end
plates 197a, 197b and side plates 198b, both side surfaces of separating
plates 199a,
and the side surface of the inner most separating wall 199b contacting the
front
surface 46 of the adjacent pilaster block 20 so as to form roughened surface
textures
on the front and back surfaces 80, 82 of the panel blocks 18, and the front
surfaces
46 and the end surfaces 49 of the pilaster blocks 20.
An exemplary method for constructing a free-standing wall is as follows.
First, the formwork for the concrete footings 22 are formed at predetermined
locations along the fence line using suitable techniques. Re-bar 42, plates
112 and
rods 28 are placed in the formwork and thereafter concrete is introduced into
the
formwork using suitable techniques to form the footings 22. After a suitable
curing
time, vertical reinforcing members 24 are tightened into the tlzreaded
coupling
members 30.
The first course of each panel 12 is formed by laying horizontal reinforcing
members 100 along the fence line between adjacent footings and placing a row
of
panel blocks 18 over the reinforcing members 100. Alternatively, the panel
blocks
18 are positioned along the fence line and the horizontal reinforcing members
are
subsequently inserted or "threaded" through the slots 94 of the panel blocks.
In
either case, rigid plates 104, washers 106 and nuts 108 are placed on the ends
of the
reinforcing members 100, which are then tensioned as needed.
Successive courses of panel blocks 18 are formed over the first, post-
tensioned course in each panel 12. Alignment pins 52 and/or plugs 50 can be
used
to connect vertically adjacent blocks, as described above. The uppermost
course in
each panel 12 is constructed by laying a horizontal reinforcing member 100 on
the
previously installed course, laying panel blocks 18 over the reinforcing
member, and
tensioning the reinforcing member. Selected courses between the lowermost and
uppermost course in each panel 12 also can be reinforced depending on the wall
height and/or the anticipated loads on the wall.
The pilasters 14, 16 are formed by stacking the appropriate pilaster blocks on
the footings 22 in the manner described above. After the stacks of blocks are
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formed, a plate 36, a washer 38, and a nut 40 are placed on the upper end
portion of
each vertical reinforcing member 24. The nuts 40 are tightened as needed to
tension
the reinforcing members 24. Thereafter, capping blocks 128 can be placed over
the
pilasters 14, 16 and courses of capping blocks 130 can be formed on top of the
panels 12 to finish the wall.
FIG. 16 is a top plan view of another embodiment of a masonry block wall.
The wall in this embodiment includes a plurality of panels 12, a field
pilaster 150,
and a corner pilaster 152. Panels 12 are formed from courses of panel blocks
18 as
previously described. Field pilaster 150 is constructed in the same manner as
described above for pilaster 14 (FIGS. 1-3), except that a plurality of
trapezoidal
pilaster blocks 154, rather than the rectangular pilaster blocks 20, are used
for
forming pilaster 14.
As best shown in FIG. 17, the pilaster block 154 comprises opposed,
generally parallel first and second faces 156, 158, respectively, side
surfaces 164
extending between respective ends of the first and second faces 156, 158, an
upper
surface 160 and a parallel lower surface. The first face 156 has a length
(measured
between the side surfaces 164) that is less than the length of the second face
158.
The side surfaces 164 converge in a direction from the second face 158 to the
first
face 156, desirably at a 45 degree angle with respect to the second face 158.
The
illustrated pilaster block 154 also is formed with one or more openings 162
desirably
extending the entire height of the block. The openings 162 are sized to
receive a
block-connecting element for connecting vertically adjacent blocks, such as an
alignment pin 52 (FIG. 11) or an alignment plug 50 (FIG. 10).
Corner pilaster 152 is constructed from a plurality of pilaster blocks 170
(FIGS. 16 and 18). Pilaster block 170 in the illustrated configuration is
generally in
the shape of a parallelogram and comprises opposed, generally parallel first
and
second faces 172, 174, respectively, opposed, generally parallel side surfaces
176
extending between respective ends of the first and second faces 172, 174, an
upper
surface 178 and a parallel lower surface. In the illustrated embodiment, the
angle 0
between the side surfaces 176 and the first and second faces 172, 174 is about
45
degrees, although this angle could be greater or less than 45 degrees in other
embodiments. Pilaster block 170 also is formed with at least one opening 180
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desirably extending the entire height of the block. The opening 180 is sized
to
receive a block-connecting element for connecting vertically adjacent blocks,
such
as an alignment pin 52 (FIG. 11) or an alignment plug 50 (FIG. 10).
As shown in FIG. 16, the corner pilaster 152 comprises an outer portion 182
on one side of the wall structure and an inner portion 184 on the other side
of the
wall structure. The outer portion 182 is formed from two stacks of pilaster
blocks
170 positioned to form a 90-degree corner on the outside of the wall structure
and
such that the blocks 170 partially overlap the end portions of two adjacent
panels 12
oriented at a 90-degree angle with respect to each other. When stacking the
pilaster
blocks 170, either alignment pins 52 (FIG. 11) or alignment plugs 50 (FIG. 10)
can
be used, as described above in regards to stacking pilaster blocks 20.
The inner portion 184 can be formed by first splitting a plurality of pilaster
blocks 170 and stacking the split block portions in the manner shown in FIG.
16 to
close the void between the adjacent ends of the panels 12 on the inside of the
wall
structure. In lieu of splitting the pilaster blocks 170, the inner portion 184
can be
constructed from smaller blocks having the shapes of the split block portions
shown
in FIG. 16 or from blocks having various other geometric shapes.
FIGS. 19-21 show a set of tables that can be used to determine certain design
criteria for constructing a wall, according to one embodiment. The data
provided in
the tables shown in FIGS. 19-21 are for wall constructions using 5" (width) x
18"
(length) x 8" (height) panel blocks 18 (referred to as "field" blocks in the
tables)
having a 1" x 2-1/2" center slot 90, and 5" (width) x 16" (length) x 8"
(height)
pilaster blocks 20. Table 200 of FIG. 19 is a wind pressure table used to
determine
the anticipated wind pressure on the wall to be built. Using table 200, the
anticipated wind pressure for a wall is the value in table 200 corresponding
to the
wind speed and exposure level at the location where the wall is to be
constructed.
For example, if the location of a wall is subject to a wind speed of 100 mph
and a
"C" exposure level, the wall will be designed for a wind pressure of 16.64 psf
(pounds per square foot).
After the wind pressure is determined, tables 202-212 of FIG. 20 and tables
214-222 of FIG. 21 can be used to determine the reinforcement requirements for
a
desired wall height and pilaster spacing. More specifically, tables 202, 204,
206
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show design data for walls designed for a maximum wind pressure of 10.00 psf
and
a center-to-center pilaster spacing of 8.25 feet, 9.75 feet, and 11.25 feet,
respectively; tables 208, 210, 212 show design data for walls designed for a
maximum wind pressure of 13.33 psf and a center-to-center pilaster spacing of
8.25
feet, 9.75 feet, and 11.25 feet, respectively; tables 214, 216, 218 show
design data
for walls designed for a maximum wind'pressure of 16.67 psf and a center-to-
center
pilaster spacing of 8.25 feet, 9.75 feet, and 11.25 feet, respectively; and
tables 220,
222 show design data for walls designed for a maximum wind pressure of 20.00
psf
and a center-to-center pilaster spacing of 8.25 feet and 9.75 feet,
respectively.
Each table 202-222 specifies for a plurality of wall heights H (FIG. 5) the
following design criteria for constructing a wall: the diameter of the upper
and
lower rods (reinforcement members 100), the minimum spacing S (FIG. 5) for the
upper and lower horizontal rods (given in inches), the force of the horizontal
rods,
the diameter and force of the pilaster rod (reinforcing member 24) for a
single-rod
pilaster, the diameter and force of the pilaster rods for a double-rod
pilaster, the
pilaster and footing weight, the overturning moment, and the minimum width of
a
square footing (given in feet).
Additional tables can be provided for greater wind pressures and/or different
fence spans than shown in FIGS. 20 and 21. Additionally, the data provided in
tables 202-212 may vary for blocks having dimensions that are different from
those
specified.
In view of the many possible embodiments to which the principles of the
disclosed invention may be applied, it should be recognized that the
illustrated
embodiments are only preferred examples of the invention and should not be
taken
as limiting the scope of the invention. Rather, the scope of the invention is
defined
by the following claims. We therefore claim as our invention all that comes
within
the scope and spirit of these claims.
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